GIS BASED DECISION SUPPORT SYSTEM FOR SYSTEMATIZED WATER DISTRIBUTION NETWORK ASSET MANAGEMENT SYSTEM:

Abstract

Most water supply services of cities in Ethiopia are unreliable, particularly in providing an adequate amount. The reasons could be diverse and many, but the most common factors are a lack of proper operation and maintenance (O&M), and poor asset management practices of the distribution systems. These bottlenecks of service provisions have significantly influenced the overall progress of the national development, in particular, the lives of citizens. Therefore, this study aimed at alleviating water distribution related problems through providing Geographical Information System (GIS) based Decision Support System (DSS) to systematize the existing O&M method for sustainable water distribution in the Harar city. To achieve this duty, None Revenue Water (NRW) of the Harar city was analyzed using International Water Audit (IWA) method. The pipe burst rate was analyzed using excel sheet based on pipe burst history data as well. Pipe risk assessment was performed based on a new approach called T-MALDP tactic, using GIS 9.3 Index modeling. Sensitivity analysis was carried out for comparison. The hydraulic characteristic of the distribution system was simulated via Epanet. Database was prepared and suggested DSS for the water distribution O&M process. From the analysis, the NRW result, 45.27% and the burst rate 6.18/km/annum was indicated poor asset management practice. The T-MALDP pipe risk analysis result indicates 18%, imperative, 17% Desirable, 28% required monitoring and 37% no need of improvement, which map was displayed with a premium Google Earth image of the Harar town. The sensitivity of T-MALDP risk result was measured with statistical measures and map removal technique. Hence, pipe diameter imposed the highest impact on pipe vulnerability to burst followed by pipe material, pressure and traffic loading. Moreover, few significant correlations between T-MALDP parameters were found independently. Map removal sensitivity analysis was indicated that as the amount of pipe failure factors increase, the chance of getting the riskiest pipe will increase. The existing distribution system was modified and optimized. Applying GIS and DSS in the proposed O&M method will increase the efficiency and assist the water network management. The output of the research showed that, in order to improve the efficiency of the Harar town water network management, GIS, DSS and Hydraulic modeling based asset management is highly applicable.